Fuse blocks, also known as “fuse boxes” and “fuse holders,” are used in a wide variety of electrical applications to support electronic fuses that protect circuits from excess current. Fuse blocks generally comprise engaging mechanisms that each hold one electrical contact of a fuse and connect that fuse to an electrical conductor. Fuse blocks with multiple fuses and multiple contacts are known in the art.
Various designs of fuses are commercially available, including flat fuses also known as but not limited to ANL, AFS, MEGA, MIDI, CNL, CNN, etc. fuses. Flat fuses have flat electrical contacts extending externally from opposite ends of the fusible metal member inside the fuse body. The electrical contacts have slots adapted to receive screws for fastening the electrical contacts to a conductive coupler that leads to the external circuit that the fuse protects. A disadvantage of using screws or bolts to fasten flat fuses is that conduction of electrical current focuses on or near the screw body. Concentrating the current increases the temperature of the electrical contact and, therefore, its resistance to current flow. This shows up as a parasitic loss in the circuit. In systems that may operate in high-temperature environments, this added heat might be fatal to the circuit.
Another disadvantage of fuses in high-current applications is the physical size of the fuse. In automotive or automotive audio applications, for example, space is often at a premium. A large fuse generally requires a large fuse holder. A method for obtaining equivalent circuit protection in a smaller package is desired.
Yet another disadvantage of fuse blocks that impacts space usage is a lack of options for routing the input and output wires. Fuse blocks typically have one connection point to each end of the fuse. The connection point may be a bore in a solid block to which one electrical contact of the fuse is connected. The electrical conductor from the circuit is inserted into the bore and secured there by a clamp of some kind. The bore has a particular orientation in space, relative to the fuse, and the conductor may be of large diameter and, therefore, somewhat stiff over short lengths. If the electrical conductor is routed in from an inconvenient direction, a large loop may need to be made to bring the end around to align with the bore. This loop requires space that may not be available.
In many fuse block applications, a combination of different fuse sizes may be needed. A fuse block may also be used as a power distribution hub, in which one power input supplies a plurality of fuse-protected power outputs. Some fuse blocks use holders that require specialized tools for inserting and removing the fuse.
Hence, there is a need for a fuse block that minimizes space requirements. There is a further need for a compact fuse block that provides various fuse-protected outputs from a single input. There is yet a further need for a fuse block that provides options for input and output wire routing. There is yet another need for a fuse block that allows insertion and removal of fuses without special tools. Yet another need is for a fuse block that contacts both of the full flat faces of a flat fuse electrical contact to minimize current concentration and heat production.